Computing devices are programmable machines capable of carrying out a sequence of arithmetic or logical operations. Some computing devices are capable of communicating with other devices. Such communication might adhere to a communication protocol. There are many communication protocols in existence for various types of communication.
Session Initiation Protocol (SIP) is a signalling protocol used for controlling communication sessions such as voice and video calls over Internet Protocol (IP). Computing devices might use SIP for various telephony signalling services.
Representational State Transfer (REST) is a software architecture style used for identifying, manipulating and transferring resource states through client-server communication. REST is stateless and is typically based on Hypertext Transfer Protocol (HTTP). Computing devices might use a RESTful protocol for various other services.